package com.chinda.common.utils;

import cn.hutool.core.util.StrUtil;
import com.chinda.common.enums.MessageEnum;
import lombok.AccessLevel;
import lombok.NoArgsConstructor;
import lombok.extern.slf4j.Slf4j;

import javax.servlet.http.HttpServletRequest;

/**
 * IP地址
 *
 * @author Wang Chinda
 * @date 2020/7/11
 * @see
 * @since 1.0
 */
@Slf4j
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public class IPUtils {

    private static final String UNKNOWN = "unknown";

	/**
	 * 获取IP地址
	 * 
	 * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
	 * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
	 */
	public static String getIpAddr(HttpServletRequest request) {
    	String ip = null;
        try {
            ip = request.getHeader("x-forwarded-for");
            if (StrUtil.isBlank(ip) || StrUtil.equalsIgnoreCase(UNKNOWN, ip)) {
                ip = request.getHeader("Proxy-Client-IP");
            }
            if (StrUtil.isBlank(ip) || ip.length() == 0 || StrUtil.equalsIgnoreCase(UNKNOWN, ip)) {
                ip = request.getHeader("WL-Proxy-Client-IP");
            }
            if (StrUtil.isBlank(ip) || StrUtil.equalsIgnoreCase(UNKNOWN, ip)) {
                ip = request.getHeader("HTTP_CLIENT_IP");
            }
            if (StrUtil.isBlank(ip) || StrUtil.equalsIgnoreCase(UNKNOWN, ip)) {
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");
            }
            if (StrUtil.isBlank(ip) || StrUtil.equalsIgnoreCase(UNKNOWN, ip)) {
                ip = request.getRemoteAddr();
            }
        } catch (Exception e) {
        	log.warn(MessageEnum.SYS_CHECK_0014.getMsg(), e);
        }
        
        return ip;
    }
	
}
